PROJECT SUMMARY/ABSTRACT: Obesity is a national epidemic that shows no sign of abating. The 2011 Strategic Plan for NIH Obesity Research stressed the need for research on new prevention and treatment programs, and we responded to this call in 2014 with the PREPARE randomized, controlled trial (NIDDK R01DK0099882). Because mothers? weight, diet, and physical activity at conception and in early pregnancy impact the metabolic milieu in which the fetus starts its development, the goal of the PREPARE intervention is to help women who are overweight or have obesity improve diet and physical activity habits and lose weight prior to becoming pregnant. The intervention, which is based on the behavior modification paradigm, utilizes telephone-based counseling conducted by health coaches as well as a personalized website. Thus, it can be delivered in any location and implemented regionally and/or nationally. The program has helped women lose weight before pregnancy and avoid excessive gestational weight gain in early pregnancy. In addition, participants rate the program very favorably. We hypothesize that intervening on women before pregnancy is the key to breaking the multigenerational cycle of obesity. However, PREPARE trial data collection ends at delivery. The PREPARE Observational (OS) cohort study would begin as the trial winds down, allowing us to follow women and their offspring for 3 years after delivery. The study would include an in-person research visit at 3 years and the collection and analysis of medical record weights for 3 years after delivery in order to determine the longer-term effect of the PREPARE intervention on weight, diet patterns, and physical activity levels of mothers and their offspring. Should it prove effective over the long term, our intervention would be a valuable tool in disrupting the multigenerational cycle of obesity.